The most common use is just to insert as an inline formula.
We can also do the display formula:

(1)

We can also insert shifted down, or insert a shifted up and rescaled formula: , if we ever need
to do such an adjustment.

We can also temporarily change the default size of the formulas. For example, this paragraph is
typeset using small font. The formula comes out smaller because we changed the default size.
After we restore the default size
is of the normal size.